1. Field of the Invention
The present invention relates to a structure of an optical transceiver, in which an optical sub-module is fixed to the transceiver without mechanical stress.
2. Related Prior Art
The United States Patent, U.S. Pat. No. 5,943,461, has disclosed an optical transceiver installing optical modules with the pig-tailed type structure for the optical transmission and the optical reception. Optical connectors provided in the end of the pig-tail fiber pulled out from each optical module are set to the housing. A multi-source agreement for such multifunctional optical transceiver has been ruled in the field and published as the X2 standard (X2-MSA). This standard rules the transmission speed of 10 GHz, the pin-assign for the electronic specification, while for the mechanical specification, the dimensions of the housing, the type of the optical and the electrical connectors, and the installing condition of the transceiver with respect to the host system are ruled.
To realize the transmission speed of 10 GHz or higher, a particular electronic circuit used therein is necessary. Especially, the power consumption of devices far increases compared with the case that the transmission speed is 1 GHz or less. Moreover, since the multifunction characteristic in the optical transmission is also required in such high performance transceiver, the optical coupling with the optical fiber is necessary to be further accurate. The optical transceiver is requested to satisfy not only the accurate thermal coupling between members for the increasing power consumption to conduct heat generated by devices but also the accurate optical coupling with respect to the optical fiber.
In the conventional optical transceiver, two subjects, the accurate thermal coupling and the accurate optical coupling, have been antithetical. When the assembly of the optical transceiver is carried out by taking the thermal coupling primarily into consideration, the accurate optical coupling may be not always obtained. Rather, the coupling characteristic inferior to the optimal one is often encountered. Contrary, when the optical coupling is the first priority, the heat dissipation is rarely achieved with acceptable efficiency. The present invention relates to a novel structure to solve the contrary subjects, the accurate optical coupling and the accurate thermal coupling between the optical sub-module and the housing, in particular, a structure for installing the optical transmitting module within the housing, which has a severe thermal condition compared to the optical receiving module.